Hair drug testing: Many street drugs (or their breakdown products in the body) are absorbed into the hair. A sample of hair can be tested for recent drug use. Hair analysis: Testing of hair for toxic exposures, such as lead or mercury poisoning.
Gas Water Heater, water not hot enough-Thermostat or Sediment. The dip tube probably disintigrated. The dip tub sends cold water to the bottom of the tank for heating when its heated it rises to the top of the tank. Its possible that the dip tube broke of and now you have cold water mixing with the hot water on top.
Carbon monoxide leaks. A gas water heater that has been neglected, improperly installed or poorly vented could leak carbon monoxide, which can be downright deadly. Carbon monoxide (CO) is an odorless, colorless gas produced from burning fuels.